Guo Yuan-ji, Wen Le-ying, Wang Min, Zhang Ye, Guo Jun-feng, Li Zi
Department of Influenza, National Institute of Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 100052, China.
Zhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi. 2003 Dec;17(4):315-8.
To understand the origin of hemagglutinin (HA), and neuraminidase (NA) gene of swine influenza A (H1N1) viruses isolated in pigs in mainland China in 2002 and reveal the reason of pathogenesis of them in pigs.
The target gene amplified by PCR,PCR product was linked with PGEM-T Easy Vector(Promega company, USA) at 4? degrees C, the recombined plasmid was transferred into DH 10B bacteria, positive colonies were selected and identified them with restriction enzyme. Afterwards, they were sent to Liu He Tong company in Beijing for testing nucleotide sequence. Finally, phylogenetic analysis of the sequencing data was performed with MegAlign (Version 1.03)and Editseq (Version 3.69) software.
The HA and NA genes of three strains of swine influenza A (H1N1) viruses isolated from pigs in China were closely related to those of swine influenza A (H1N1) virus, but different from those of avian or human influenza A (H1N1) virus. The swine strain of influenza A (H1N1) virus isolated in 2002 was derived from swine influenza A (H1N1) virus circulated in pigs in China in 1991. Since the antigenic drifts of HA and NA proteins of the new isolates occurred, their activity in pigs is increasing and they can cause disease in pigs.
The HA and NA genes of three strains of influenza A (H1N1) virus tested were identified to be derived from those of swine influenza A (H1N1) virus. The increased activity and pathogenesis of them in pigs were most likely due to antigenic drifts of HA and NA proteins of the new isolates.
了解2002年在中国内地猪群中分离出的甲型H1N1流感病毒血凝素（HA）和神经氨酸酶（NA）基因的起源，并揭示其在猪体内致病的原因。
采用PCR扩增目的基因，PCR产物于4℃与PGEM-T Easy载体（美国Promega公司）连接，重组质粒转入DH 10B细菌，筛选阳性菌落并用限制性内切酶进行鉴定。之后，将其送北京六合通公司进行核苷酸序列检测。最后，用MegAlign（版本1.03）和Editseq（版本3.69）软件对测序数据进行系统发育分析。
从中国猪群中分离出的3株甲型H1N1流感病毒的HA和NA基因与甲型H1N1流感病毒的基因密切相关，但与禽或人甲型H1N1流感病毒的基因不同。2002年分离出的猪源甲型H1N1流感病毒株源自1991年在中国猪群中传播的甲型H1N1流感病毒。由于新分离株的HA和NA蛋白发生了抗原漂移，它们在猪体内的活性增强，能够引起猪发病。
所检测的3株甲型H1N1流感病毒的HA和NA基因被鉴定为源自甲型H1N1流感病毒。它们在猪体内活性和致病性的增加很可能归因于新分离株HA和NA蛋白的抗原漂移。
